Pests, whether urban or agricultural, has ever been the subject of concern and the act of controlling and extinguishing these pests has always been exercised by man.
Over time, various techniques have been used for dispensing pesticides.
Typically the pesticides are presented in a fluid or finely divided powder forms. This document is focused on pesticides in a fluid form.
In the prior art technique, it can be found several documents that disclose methods and equipment for dispensing these fluid products in the form of mist. A first group usually uses a pumping system with high pressure which may have features pulsing or vibrating, which leads the fluid to dispersion devices in order to reduce it to very small particles which are then carried by the air jet generated by one of the following devices: a large-capacity blower or air coming from a compressor and tank assembly.
These particles of fluid pesticide must have a very small size in order to be light enough to remain suspended in the air for some time. However, the existing equipment are usually large and heavy, which are only possible to be carried by trucks or vans of medium size, which still must travel in low speed. The applying of this technique, however, has as a negative side effect regarding the formation of a residual layer of fluid pesticides in the environment, which may cause damages to man caused by the possible contact therewith.
This problem was attempted to be solved by installing additional sensors and circuitry to analyze the size of the droplets emitted by the device, sophisticating somewhat the equipment, but on the other hand, complicating further the system and adding more items likely to maintenance.
Another limitation is the fact that the trucks or vans adapted for this purpose do not can travel on rough terrain. There are attempts to use lighter vehicles with four wheels, but even so, the items relating to safety and quick maneuverability remain as a source which prevents such attempts in any scenario more complicated.
Another technique used to dispense fluid pesticide is known as thermo-nebulization.
Typically this kind of technique involves heating a fluid until vaporize it and further carrying this hot steam to the application area.
The state of art technique already know many systems to perform thermal fogging, which are from devices that can be conducted by an operator, to devices coupled to the trucks, SUVs, planes, tractors and other vehicles specially adapted for this purpose.
Observing the operation of the thermo-nebulizers, it is worth quoting as the more common those who are engaged in the vehicles bucket. These thermo-nebulizers devices, which usually work with an autonomous motorization, are usually heavy and made up of several stages of components.
Moreover, the vehicles that carry them have limitations on their autonomy characteristics for use due to own ground wherever they go, avoiding usually the use of rudimentary trails or rough places. There is also the possibility that the bumps on the way can displace the thermo-nebulizer, damaging it to the point of causing serious accidents once it is working with potentially flammable hot products. Moreover, the possibility of occurring displacements of these equipments in terms of generating cold mist also exists.
However, vehicles equipped with this kind of equipment who works in hot conditions, had discontinued its use mainly in urban areas. A first reason was due to the mist formed, which by being very dense and high dispersion time, diminishing visibility of other vehicles that need to travel on the street that was being fumigated. A second reason was due by the very people which by feeling uncomfortable with the smoke, had to shut the windows of their homes in order to prevent this smoke to come into their homes.
In a simple analysis, the hot system would be more adapted to environments not inhabited, such as crops; however, the fact of this crop to be in a rugged terrain, where a utility vehicle could not move so well across it, still represents an insurmountable barrier.
Trying to overcome the limitation described just above, proposals have emerged aiming to simplify operation and increase the ability to reach some places hitherto inaccessible.
The thermo-nebulizer became a portable device, commonly known as costal thermo-nebulizer.
Basically the operational principle was maintained using a engine, a reservoir, a spark system where the insecticide burn, an exhaust pipe and a manual transmission fluid system to be manipulated by an operator.
The main problems arising from this kind of proposal resides on the weight of the equipment, which is still very high, which causes operator fatigue, and the need for an operator with a certain skill when handling the equipment. An undue functioning of the equipment caused by the lacking skill of the operator, could transform this kind of equipment on a flamethrower.